.nav{
    background-color: aquamarine;
}
.shang{
    /* width: 100%; */
    width: 350px;
    height: 25px;
    /* background-color: aqua; */
    margin-left: 10px;
    margin-top: 10px;
    padding-top: 10px;
}
.zhong{
    margin-top: 20px;
    .zhonga{
        font-weight: 800;
        margin-left: 10px;
        font-size: 20px;
    }
    .zhongb{
        margin-top: 10px;
        /* margin-left: 10px; */
        padding: 10px;
        display: grid;
        grid-template-columns: 1fr 1fr 1fr;
        gap: 10px;
        .zhongc{
            height: 40px;
            color: #000;
            text-align: center;
            font-size: 20px;
            padding: 10px;
        }
    }
    
}

.xia{
    background-color: aqua;
    height: 610px;
}